5
Service Guide
70
Keysight U8001A/U8002A User’s and Service Guide
Constant Current (CC) Verification
Current programming and readback accuracy
This test is to verify that the current programming and readback accuracy are
within published specifications. The accuracy of the current monitoring resistor
must be 0.1% or better.
Procedures:
1
Power-off the power supply and connect a 0.01
Ω
current shunt monitoring
resistor (R
M
) across the output to be tested and a DMM across the current
monitoring resistor (R
M
).
2
Power on the power supply.
3
When the power supply is in limit mode, program the output voltage to
maximum programmable value and the current to 0 A.
4
Enable the output.
5
Wait for a few seconds for the output of the power supply to settle. Make sure
that the power supply is in CC mode.
6
Divide the voltage drop (DMM reading) across the current monitoring resistor
(R
M
) by its resistance to convert to amps and record this value (I
O
). This value
should be within the limit of 0 A ±20 mA.
7
When the power supply is in meter mode, record the current reading displayed
on the front display of the power supply. This value should be within the limit
of I
O
±20 mA.
8
Disable the output.
9
When the power supply is in limit mode, program the output current to full
rated value, i.e. 3 A for U8001A and 5 A for U8002A.
10
Enable the output.
11
Wait for a few seconds for the output of the power supply to settle. Make sure
that the power supply is in CC mode.
